The injection molding device which injects resin to fill it in metallic molds to form it into a desired shape is capable of stably forming the resin into even a complex shape, and is hence employed to produce various members including parts of articles for daily use and electronic appliances.
A so-called insert molding device which inserts a film in metallic molds for injection molding and injects resin in the molds to thereby form a desired member makes it possible to also conduct surface decoration by the film in the same process as the member forming process, and hence is employed to produce housings and exterior trim items for electronic appliances, interior trim members for cars, and the like.
The film to be inserted in the molds in the insert molding is generally in an elongated form wound up in the shape of a roll or is a sheet of film having a predetermined size not associated with a member to be formed; hence, in a state in which the film is inserted and the injection is conducted thereto, the film is not appropriate for the use as a member. That is, a remaining portion of the film exceeding the size of the molds fixes onto a periphery of the member.
To avoid such state, the remaining portion of the film is cut off after the injection molding in some cases. Further, the injection molding is conducted depending on cases after the film which is beforehand shaped to conform to the shape of the molds in advance and which is trimmed to match the size of the molds is inserted in the molds. When these schemes are employed, a second process is disposed before and after the injection molding, making the processes complicated; hence, these schemes are not suitable for mass-production and cost reduction.
On the other hand, Patent Document 1 describes an injection molding device which inserts a film including the remaining portion thereof in the metallic molds to achieve cutoff of the film and the injection molding in one process.